Item 4. The Birth of Jidoka

Completed in 1897, the Toyoda Power Loom, Japan's first self-powered loom, drew acclaim for its ability to produce high quality cotton cloth in a stable manner, and gained widespread public attention.

The Toyoda Power Loom featured a weft halting device1 which automatically stopped the machine when the weft thread in the shuttle broke or was exhausted.

In power looms, if the weft or the warp thread breaks and the machine is not stopped immediately, faults can occur, such as the warp continuing to be incorporated into the fabric without the weft, or the broken warp thread being left out, leading to the output of damaged fabric. Sakichi Toyoda researched systems to prevent such faults, and in addition to the weft halting device mentioned above, also made several other inventions and improvements, including a system for maintaining a constant tension of the warp thread to prevent breakages, and a warp halting device to stop the loom when the warp thread broke.

The Toyoda Power Loom released by Toyoda Shokai in 1905 was not an automatic loom, but a so-called "regular" power loom, and incorporated features such as those described above to prevent defects. According to the instruction manual2 for the Toyoda Power Loom, the following were the model's main features:

1.The warp tension controller automatically maintained the warp output at a constant tension. This resulted in less frequent breakage of the warp thread, reducing loom downtime and producing other benefits. In terms of product value, fabrics had a consistently fine texture and uniform quality.

2.The loom featured a warp halting device which automatically shut down the machine when the warp thread broke. This meant that the machine did not have to be constantly watched, allowing a single operator to run several looms at once. Also, quality defects such as missing or tangled threads decreased, reducing the likelihood of damage to the fabric.

3.A weft halting device halted the loom when the weft thread broke or ran out. As in item 2, this eliminated the need for the machine to be constantly watched.

In the "Instruction Manual for Toyoda Power Loom" (edited by Sakichi Toyoda) released by Toyoda Shokai in September 1905, the characteristics of the model are described as follows:The 1905 Toyoda Power Loom was designed to be affordable, with specifications suited for family-run operations.- This loom was designed as a cotton weaving machine capable of producing 20 or 30 percent profits in times when poor economic conditions make hand weaving unprofitable.- The easy-to-use and state-of-the-art warp halting device featured in this loom offers the following benefits:1) The machine stops automatically if the warp thread breaks2) There is no need for the machine to be constantly watched, allowing a single operator to handle several looms3) Does not cause damage to the cotton; therefore finished products can be sold at higher prices4) No need for reworking of defects; therefore there is no waste of weft thread5) Easy to pass thread through the heddle- This loom offers the following new benefits due to added functions such as a warp tension controller and an opening device1) Prevents breakage of the warp thread2) Reduction in warp thread breakage and larger shuttle means less stoppage time and improved machine output3) The warp thread is automatically controlled at a constant tension regardless of amount of reeling4) Thick cotton yarn can be woven, without warp thread breakage5) The constant tension provided in iii) eliminates unevenness, creates excellent texture, allows for a constant width and length of fabric, and produces selvages that appear as if they were cleaning cut- The loom incorporates an innovative new weft halting device that immediately stops the machine when the weft thread breaks or runs out. The machine does not need to be constantly watched and cut out trouble, allowing several machines to be operated by a single worker. In addition, the reduction in lost operating time increases fabric output per machine.

3

Taiichi Ono, a supporter of the Toyota Production System, was an engineer who transferred from Toyoda Boshoku Corporation to Toyota Motor Co., Ltd. He was an export on looms and a promoter of the jidoka concept. An article entitled “The Inspiration for Jidoka” submitted by then Managing Director Ono to the “Word of the Month” column in Toyota Management (March 1969), an internal newsletter, that the design concepts of the weft halting device and warp halting device invented by Sakichi were the origins of the jidoka concept.